From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 19/30] KVM: PPC: e500mc: add load inst fixup
Date: Fri, 17 Feb 2012 17:17:02 -0600 [thread overview]
Message-ID: <4F3EDFEE.3040106@freescale.com> (raw)
In-Reply-To: <1329498837-11717-20-git-send-email-agraf@suse.de>
On 02/17/2012 11:13 AM, Alexander Graf wrote:
> There's always a chance we're unable to read a guest instruction. The guest
> could have its TLB mapped execute-, but not readable, something odd happens
> and our TLB gets flushed. So it's a good idea to be prepared for that case
> and have a fallback that allows us to fix things up in that case.
>
> Add fixup code that keeps guest code from potentially crashing our host kernel.
>
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
> arch/powerpc/kvm/bookehv_interrupts.S | 30 +++++++++++++++++++++++++++++-
> 1 files changed, 29 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
> index 63023ae..e0f484c 100644
> --- a/arch/powerpc/kvm/bookehv_interrupts.S
> +++ b/arch/powerpc/kvm/bookehv_interrupts.S
> @@ -28,6 +28,7 @@
> #include <asm/asm-compat.h>
> #include <asm/asm-offsets.h>
> #include <asm/bitsperlong.h>
> +#include <asm/thread_info.h>
>
> #include "../kernel/head_booke.h" /* for THREAD_NORMSAVE() */
>
> @@ -171,9 +172,36 @@
> PPC_STL r30, VCPU_GPR(r30)(r4)
> PPC_STL r31, VCPU_GPR(r31)(r4)
> mtspr SPRN_EPLC, r8
> +
> + /* disable preemption, so we are sure we hit the fixup handler */
> +#ifdef CONFIG_PPC64
> + clrrdi r8,r1,THREAD_SHIFT
> +#else
> + rlwinm r8,r1,0,0,31-THREAD_SHIFT /* current thread_info */
> +#endif
> + lwz r6,TI_PREEMPT(r8)
> + addi r7,r6,1
> + stw r7,TI_PREEMPT(r8)
Whitespace
The preempt count had better already be zero here, so we can just store
1 now, and 0 later, and avoid the stall on load results.
> +
> isync
> - lwepx r9, 0, r5
> +
> + /*
> + * In case the read goes wrong, we catch it and write an invalid value
> + * in LAST_INST instead.
> + */
> +1: lwepx r9, 0, r5
> +2:
> +.section .fixup, "ax"
> +3: li r9, KVM_INST_FETCH_FAILED
> + b 2b
Please tab after the opcode
> +.previous
> +.section __ex_table,"a"
> + PPC_LONG_ALIGN
> + PPC_LONG 1b,3b
> +.previous
> +
> mtspr SPRN_EPLC, r3
> + stw r6,TI_PREEMPT(r8)
> stw r9, VCPU_LAST_INST(r4)
Whitespace
-Scott
next prev parent reply other threads:[~2012-02-17 23:17 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-17 17:13 [PATCH 00/30] KVM: PPC: e500mc support Alexander Graf
2012-02-17 17:13 ` [PATCH 01/30] powerpc/booke: Set CPU_FTR_DEBUG_LVL_EXC on 32-bit Alexander Graf
2012-02-17 17:13 ` [PATCH 02/30] powerpc/e500: split CPU_FTRS_ALWAYS/CPU_FTRS_POSSIBLE Alexander Graf
2012-02-17 17:13 ` [PATCH 03/30] KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv Alexander Graf
2012-02-17 17:13 ` [PATCH 04/30] KVM: PPC: booke: add booke-level vcpu load/put Alexander Graf
2012-02-17 17:13 ` [PATCH 05/30] KVM: PPC: booke: Move vm core init/destroy out of booke.c Alexander Graf
2012-02-17 17:13 ` [PATCH 06/30] KVM: PPC: e500: rename e500_tlb.h to e500.h Alexander Graf
2012-02-17 17:13 ` [PATCH 07/30] KVM: PPC: e500: merge <asm/kvm_e500.h> into arch/powerpc/kvm/e500.h Alexander Graf
2012-02-17 17:13 ` [PATCH 08/30] KVM: PPC: e500: clean up arch/powerpc/kvm/e500.h Alexander Graf
2012-02-17 17:13 ` [PATCH 09/30] KVM: PPC: e500: refactor core-specific TLB code Alexander Graf
2012-02-17 17:13 ` [PATCH 10/30] KVM: PPC: e500: Track TLB1 entries with a bitmap Alexander Graf
2012-02-17 17:13 ` [PATCH 11/30] KVM: PPC: e500: emulate tlbilx Alexander Graf
2012-02-17 17:13 ` [PATCH 12/30] powerpc/booke: Provide exception macros with interrupt name Alexander Graf
2012-02-17 17:13 ` [PATCH 13/30] KVM: PPC: booke: category E.HV (GS-mode) support Alexander Graf
2012-02-17 21:12 ` Scott Wood
2012-02-20 11:40 ` Alexander Graf
2012-02-17 17:13 ` [PATCH 14/30] KVM: PPC: booke: standard PPC floating point support Alexander Graf
2012-02-17 17:13 ` [PATCH 15/30] KVM: PPC: e500mc support Alexander Graf
2012-02-17 17:13 ` [PATCH 16/30] KVM: PPC: e500mc: Add doorbell emulation support Alexander Graf
2012-02-17 21:55 ` Scott Wood
2012-02-17 21:57 ` Scott Wood
2012-02-20 11:49 ` Alexander Graf
2012-02-20 15:39 ` Scott Wood
2012-02-20 15:42 ` Alexander Graf
2012-02-17 17:13 ` [PATCH 17/30] KVM: PPC: e500mc: implicitly set MSR_GS Alexander Graf
2012-02-17 17:13 ` [PATCH 18/30] KVM: PPC: e500mc: Move r1/r2 restoration very early Alexander Graf
2012-02-17 17:13 ` [PATCH 19/30] KVM: PPC: e500mc: add load inst fixup Alexander Graf
2012-02-17 23:17 ` Scott Wood [this message]
2012-02-17 17:13 ` [PATCH 20/30] KVM: PPC: rename CONFIG_KVM_E500 -> CONFIG_KVM_E500V2 Alexander Graf
2012-02-17 17:13 ` [PATCH 21/30] KVM: PPC: make e500v2 and e500mc mutually exclusive Alexander Graf
2012-02-17 22:13 ` Scott Wood
2012-02-17 17:13 ` [PATCH 22/30] KVM: PPC: booke: remove leftover debugging Alexander Graf
2012-02-17 17:13 ` [PATCH 23/30] KVM: PPC: booke: deliver program int on emulation failure Alexander Graf
2012-02-17 17:13 ` [PATCH 24/30] KVM: PPC: booke: call resched after every exit Alexander Graf
2012-02-17 23:00 ` Scott Wood
2012-02-20 13:17 ` Alexander Graf
2012-02-20 17:18 ` Scott Wood
2012-02-17 17:13 ` [PATCH 25/30] KVM: PPC: booke: BOOKE_IRQPRIO_MAX is n+1 Alexander Graf
2012-02-17 17:13 ` [PATCH 26/30] KVM: PPC: bookehv: fix exit timing Alexander Graf
2012-02-17 17:13 ` [PATCH 27/30] KVM: PPC: bookehv: remove negation for CONFIG_64BIT Alexander Graf
2012-02-17 17:13 ` [PATCH 28/30] KVM: PPC: bookehv: remove SET_VCPU Alexander Graf
2012-02-17 17:13 ` [PATCH 29/30] KVM: PPC: bookehv: disable MAS register updates early Alexander Graf
2012-02-17 17:13 ` [PATCH 30/30] KVM: PPC: bookehv: add comment about shadow_msr Alexander Graf
-- strict thread matches above, loose matches on Subject: below --
2012-02-17 16:56 [PATCH 00/30] KVM: PPC: e500mc support Alexander Graf
2012-02-17 16:56 ` [PATCH 19/30] KVM: PPC: e500mc: add load inst fixup Alexander Graf
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